Photocatalytic reduction has been applied for the removal of TcO 4 − /ReO 4 − due to the green and eco-friendly advantages, but reports on photocatalytic reduction for TcO 4 − /ReO 4 − were few, owing to the limited availability of suitable photocatalytic materials. Herein, two different Conjugated Microporous Polymers (CMPs) were constructed between triazine and thienothiophene using vinyl (Vi-TMT-TT) and phenyl (Ph-TBT-TT) groups as linker and were firstly used for the removal of ReO 4 − , respectively. Vi-TMT-TT was rich in triazine units with higher density and greater electronegativity, which was more likely to generate more protonation sites and was conducive to the adsorption of ReO 4 − . After light exposure, the completely planar framework enhanced the photocatalytic activity of Vi-TMT-TT, achieving photo-enhanced rhenium recovery (92 ± 1)% removal in 100 ppm solutions, pH = 3). By the characterizations such as XPS, pH-zeta, EPR, and combined with DFT calculations, the mechanism was that ReO 4 − was firstly adsorbed on the triazine unit and reduced to insoluble Re(IV) by photogenerated single electrons in nitrogen atmosphere. The findings provide new insights into the design of materials for TcO 4 − /ReO 4 − removal.
